Help needed with e_adept_request_expired error message

[Celine_Helene]

I am trying to open my first ACSM ebook, and keep on getting this error message. I am using a standard PC laptop running Microsoft Office and the likes, not Nook or an e-reader. I had no problems setting up Adobe Digital Edition and registering my laptop with Adobe. That seems to work fine. 

However, I cannot open the one ACSM book I bought as I keep getting this request expired message.  I am utterly baffled by the 'check your Time zone' solution. I am based in the UK, bought the ACSM on a UK website to read on my laptop. Am I meant to set my time zone to that of Adobe in the US? Should it be the same as that of the website I bought the book from?? How do I know what. or rather whose, time zone I should be on? I am after all in the correct time zone for where I live!

My internet time settings are set to  synchronise with 'time.windows.com'. I really really do not know what to do. I have re-synchronised the time, deleted then redownloaded the file, nothing will work. It has been three days now, and I still can't open the book.

[Mylenium]

The ebook store you bought it from may use invalid/ outdated certificates. Check their knowledge base or contact their support.

Mylenium

[Jeff A Wright]

Which operating system are you using?  Is the time zone set to the same time zone you are located in?

[YuvrajShinde071]

It would be great and helpful if you upload a screen shot of  the  error message you are getting.